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path: root/drivers/gpu/drm/drm_modes.c
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Diffstat (limited to 'drivers/gpu/drm/drm_modes.c')
-rw-r--r--drivers/gpu/drm/drm_modes.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 173b7d335834..f64ac86deb84 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -165,6 +165,7 @@ struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay,
unsigned int vfieldrate, hperiod;
int hdisplay_rnd, hmargin, vdisplay_rnd, vmargin, vsync;
int interlace;
+ u64 tmp;
/* allocate the drm_display_mode structure. If failure, we will
* return directly
@@ -322,8 +323,11 @@ struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay,
drm_mode->vsync_end = drm_mode->vsync_start + vsync;
}
/* 15/13. Find pixel clock frequency (kHz for xf86) */
- drm_mode->clock = drm_mode->htotal * HV_FACTOR * 1000 / hperiod;
- drm_mode->clock -= drm_mode->clock % CVT_CLOCK_STEP;
+ tmp = drm_mode->htotal; /* perform intermediate calcs in u64 */
+ tmp *= HV_FACTOR * 1000;
+ do_div(tmp, hperiod);
+ tmp -= drm_mode->clock % CVT_CLOCK_STEP;
+ drm_mode->clock = tmp;
/* 18/16. Find actual vertical frame frequency */
/* ignore - just set the mode flag for interlaced */
if (interlaced) {